Just for the record: your certification, the one you paid four figures for, is meaningless.
Sure, it might mean something to an employer somewhere, but not to the employer you'll love to work for. After all, if your employer values certification above actual ability, it's probably not a great place to work. They're likely to value TPS reports and other meaningless formalities just as highly, and guess who's going to get stuck writing them? Do you think that love of paper over ability suddenly stops when you waltz through the door? And if they do value ability over paper, your certification won't be why you got hired. (Actually, the people I respect most say that certifications actually reduce their interest in a candidate.)
Sure, it might mean that you learned something. It certainly means you passed a test, if there was one. But the certificate didn't get you to learn--you got you to learn. And you'd better believe that you can find good training cheaper when there's no certification attached. In my survey of the courses offered at Agile University last year, Certified ScrumMaster courses typically cost $200 more than comparable courses without certification.
(I'm not trying to pick on Scrum here. It's just the certification program I know best.)
Sure, it might mean that the person you learned from knew what they're talking about. It probably means the course materials were vetted by someone who knew what they were talking about. But that doesn't mean the instructor really knew what they were doing. Certification makes a lot of people a lot of money. It's far more lucrative than hands-on coaching, although the latter tends to be more effective and requires more practical ability. As a result, even the most principled among us tend to gravitate towards providing certification, and the field is awash in bottom-feeders. Many professional trainers have no real-world experience in the subjects they teach. Even the best typically haven't worked in a development shop for years.
A good employer is important. Learning is valuable. Good mentors are priceless. And I'm afraid to say that your certification means none of these things. At best, it was a side effect. At worst--a waste.
PS: This rant inspired by Cory Foy's recent essay and "Uncle Bob" Martin's comments on that essay.
PPS: If you liked this, you may also be interested in Why I Don't Provide Agile Certification.